Morphanthridine carboxylic acid and derivatives



United States Patent 3,316,246 MORPHANTHRIDINE CARBOXYLIC ACID AND DERIVATIVES Alexander E. Drukker, Milwaukee, and Claude I. Judd,

Mequon, Wis., assignors to Colgate-Palmolive Compauy, New York, N.Y., a corporation of Delaware No Drawing. Filed Feb. 8, 1966, Ser. No. 525,869 6 Claims. (Cl. 260-239) This is a continuation-in-part of application Ser. No. 438,383, filed Mar. 9, 1965.

This invention relates to novel morphanthridine derivatives and processes of preparing such derivatives. More particularly, this invention is concerned with morphanthridine-ll-carboxylic acid and its derivatives, novel intermediates associated with the preparation of these compounds, processes of producing the intermediates and final compounds and pharmacologic and therapeutic uses for such compounds.

The novel compounds of this invention have the formula wherein A and A are hydrogen, a halo group such as the chloro and bromo, a lower alkoxy such as'methoxy and ethoxy, a lower [alkyl such as methyl and butyl, a lower alkyl-thio such as thiomethyl and thioethyl and trifluoromethyl; R is hydrogen, a straight or branched chain lower alkyl of from 1 to 8 carbon atoms such as methyl, ethyl, isopropyl and butyl, an :aralkyl such as benzyl or alkyl; and Y is a member selected from the class consisting of -OH, -OCH CN and the group wherein R and R are the same or different groups including hydrogen, a lower alkyl such as methyl, ethyl, propyl, isopropyl or butyl, a lower alkenyl such as lallyl, an aryl such as phenyl or a nuclear-substituted phenyl, an aralkyl such as benzyl, phenethyl, phenylisopropyl, diphenylmethyl, trityl, naphthylmethyl, a cycloalkyl, pargroups in which M alkyl or represents a group such as morpholino, pyrrolidino, piperidino, piperazino, l,2,3,4 tetrahydroquinolino, 4-lower alkyl piperazino such as 4-methylpipe-razino, 4-(phenyllower -alkyl)-piperzino such s 4-benzyl-piperazino and 4-(alpha-methylphenethyl)-piperazino and 4 (hydroxylower alkyD-piperazino such as 4-(2-hydroxy-1-ethyl)piperazino.

The compounds of the present invention may be prepared by treating a 5-substituted-5,6--dihydromorphanthridine with an alkali metal alkyl or aryl compound to form the ll-alkali metal salt and then carbonating said compound to form the corresponding novel carboxylic acid (i.e., those compounds in which Y is OH). The acid can then be converted to the cyano methyl ester (i.e., those compuonds in which Y is -OCH CN). The esters in turn can be treated With amines to form the amidesi.e., those compounds in which 3 The process may be represented as follows:

r r A A1 A A1 H 10 R2 H N oomoN wherein A, A R, and

have their assigned values and M is an alkali metal such as lithium.

The ll-alkali metal salts of S-substituted-S,6dihydromorphanthridine which may be used in the process are prepared by reacting a S-Substituted 5,6-dihydromorphanthridine with an alkali metal lower alkyl or aryl compound such as butyl lithium or phenyl lithium. The reaction is readily effected by bringing the reactants together in an inert anhydrous liquid reaction medium such as pentane, hexane, ethyl ether, xylene, toluene, tetralin, cumene or tetrahydrofuran, and compatible mixtures of such solvents. The reaction can be effected at room temperature or elevated temperatures depending on the reactivity of the alkali metal compound used in the process. The reac- S-methyl-S,6-dihydromorphanthridine, -ethyl-5,6-dihydromorphanthridine, S-isopropyl-S ,6-dihydromorphanthridine, S-benzyl-S,6-dihydromorphanthridine, 5-phenethyl-5,6-dihydromorphanthridine, S-allyl-S,6-dihydromorphanthridine, and 5 -cinnamyl-5 ,6-dihydromorphanthridine.

The conversion of the ll-alkali metal salt of a S-substituted-S,6-dihydromorphanthridine to the corresponding carboxylic acid is efiected by a carbonation procedure. The ll-alkali metal salt is dissolved in an inert anhydrous liquid reaction medium and the solution is treated with a large excess of solid carbon dioxide. The excess carbon dioxide is allowed to evaporate and the residue is treated with a dilute alkali metal carbonate solution, preferably dilute potassium carbonate solution. The aqueous layer which forms is then separated, acidified to a pH of about 2 to 3 with an acid such as hydrochloric acid, and extracted with a suitable solvent such as benzene. The benzene fraction is then concentrated to yield the crude acid and, if desired, the acid further purified by crystallization from a suitable solvent, e.g. petroleum ether-methanol.

Some of the novel carboxylic acids which may be prepared in this manner are the following:

and S- henethyI-S,G-dihydromorphanthridine ll-carboxylic acid.

The S-substituted-S,6-dihydromorphanthridine 11-carboxylic acid may be readily converted to the corresponding cyanomethyl ester by treating the acid with a haloa-cetonitrile such as chloroacetonitrile or bromoacetonitrile in an inert solvent, preferably in the presence of a hydrogen halide acceptor, e.g. triethylamine. The reaction is promoted by heating, and reflux temperatures are preferred. When the reaction is substantially complete the corresponding cyanomethyl ester can be recovered from the reaction mixture by conventional techniques, e.g., solvent extraction followed by crystallization procedures.

Some of the 5-substituted-5,6-dihydr0morphanthridinell-carboxylate cyanomethyl esters which may be prepared in this manner are the following:

cyanomethyl S-methyl-S,6-dihydromorphanthridine-11- carboxylate,

cyanomethyl 5-isopropyl-5,6-dihydromorphanthridine-l1- carboxylate,

cyanomethyl 5-butyl-5,6-dihydromorphanthridine-11- carboxylate,

cyanomethyl S-benzyl-5,6-dihydromorphanthridine-1lcarboxylate, and

cyanomethyl S-phenethyl-S ,6-dihyd1'omorphanthridine-1 lcarboxylate. The S-substituted-S,6-dihydromorphanthridine carboxamide't, those compounds in which may be readily prepared by treating a corresponding ll-carboxylate cyanomethyl ester derivative with ammonia or a suitable primary or secondary amine.

Representative of the amines which may be employed in the process of the present invention are the following:

Representative of the novel amides which can be prepared by the process of the present invention are the following:

5 -methy1-5 ,6-dihydromorphanthridine-l l-carboxamide,

N-methyl-S-methyl-5,6-dihydromorphanthridine-1 l-carboxamide,

N,N-dimethyl-5-methyl-5 ,6-dihydromorphanthridinel lcarboxamide,

N-benzyl-S-methyl-S,6-dihydromorphanthridine-1l-carboxamide,

N-phenyl-S-rnethyl-5,6-dihydromorphanthridine-1 l-carboxamide,

N-methyl-N-benzyl-S ,6-dihydromorphanthridine-l l-carbox amide,

N- 5 -methyl-5 ,6-dihydro-l l-morphanthridinecarbonyl) piperidine,

N-(5-methyl-5,6-dihydro-11-morphanthridinecarbonyl) morpholine, and

4'methyll S-methyl-S ,6-dihydrol l-morphanthridinecarbonyl) -pi-perazine.

While all the compounds of the invention are useful as chemical and pharmaceutical intermediates, the novel compounds of the present invention which are amides are, in addition, promising analgetic, sedative, skeletal muscle relaxants, anticonvulsant agents and general central nervous system depressants. Threfore, they can be used in pharmacological studies and as screening agents for evaluating compounds for these activities.

The compounds can be administered to animals as pure compounds, in the form of a pharmaceutically acceptable non-toxic acid addition salt, but to obtain a more practical size to dosage relationship one or more of the compounds is combined with a suitable pharmaceutical carrier and made into unit-dosage forms. Administration can be oral or parenteral.

Pharmaceutical carriers which are liquid or solid can be used. The preferred liquid carrier is water. Flavoring materials can be included in the solutions as desired.

Solid pharmaceutical carriers such as starch, sugar and talc can be used to form powders. The powders can be used as such or be tableted, or be used to fill gelatin capsules. Suitable lubricants like magnesium stearate, binders such as gelatin and disintegrating agents, like sodium carbonate in combination with citric acid, can be used to form the tablets.

Unit dosage forms such as tablets and capsules can contain any suitable predetermined amount of one or more of the compounds and can be administered one or more at a time at regular intervals. Such unit dosage forms can contain 1 to 300 mg. or more of an active compound of this invention. The total amount of active compound administered must be ultimately fixed by reference to the animal and disease to be treated. However, about 1 to 300 mg. four times daily for a total daily dose of 4 to 1200 mg. is suitable.

, and extracted with benzene.

5-methyl-5,6-dihydromorphanthridine- 11 -carboxylic acid -'To a. solution of 4l.8 g. (0.2 mole) of 5-methyl-5,6- dihydromorphanthridine in" 250 ml. of tetrahydrof-uran is added dropwise at 10 a solution of 166 ml. of butyl lithiumsolution (0.25 mole) in 250 ml. of'ether. The resulting dark-red solution is stirred 5 hours at room temperature and poured into a large excess of solid carbon dioxide in 1 l. of ether. The excess of carbon dioxide is left to evaporate, and-the residue is treated with dilute potassium carbonate solution. The aqueous layer is separated, acidified with hydrochloric acid to pH 2-3, The benzene solution is d-ried over sodium sulfate, filtered, and concentrated. The solid resid-ue is recrystallized from 750 ml. of petroleumet-her and 125 ml. of methanol to give S-methyl- 5,6-dihydromorphanthridine 11-carboxy1ic :acid, M.P. 130 (decomposed).

Analysis.Calcd. N, 5.53.

for C16H15NO2Z Found: C, 75.91; H, 5.86;

EXAMPLE II Cywnomethyl 5-methyl-5,6-dihydromorphanthridine-I l carboxylate To 14.05 g. (0.059 mole) of 5-methyl-5,6-dihydromorphanthridine ll-carboxylic acid and 6.6 g. of triethylamine in 200 ml. of ethyl acetate is added dropwise with stirring 4.9 g. of chloroacetonitrile in 100 ml. of ethyl acetate. The solution is refluxed for 6 hours, concen- ,trated, the residue isdisso'lved in benzene, washed with C, 75.87; H, 5.97; N, 5.80.

' water, dried over potassium carbonate, filtered, and concentrated. The solid residue is recrystallized from ethan01 to give cyanomethyl S-methyl-5,6-dihydromorphanthridine-l l-carboxylate, M.P. 184.5

Analysis.-Calcd. for C H N O C, 73.95; H, 5.51; N, 9.58. Found: C, 73.47; H, 5.35; N, 9.50.

EXAMPLE III 5 -methyl-5,6-dihydrmorphanthridineJ I -carb0xamid'e A mixture of 7.2 g. (0.0246 mole) of cyanomethyl methyl 5,6 dihydromorphanth-ridine 11 carboxylate and 150 ml. of liquid ammonia are stirred in an autoclave for 18 hours. The autoclave is opened and the ammonia is evaporated at room temperature. The residue is taken up in 200 ml. of ethanol, boiled to remove the ammonium cyanide, filtered and concentrated. The residue is recrystallized from 35 ml. of give 5 methyl 5,6 dihydromorphanthridine boxamide, M.P. 146-147".

Analysis-Calcd. for C H N O: C, 76.16; H, 6.39; N, 11.10. Found: C, 76.32; H, 6.46; N, 11.01.

EXAMPLE IV S-benzyl-S,6-dihydr0m0rphanthridine-1l-carboxylz'c acid To a solution of 127.3 g. (0.465 mole) of 5-benzyl-5,6- dihydromorphanthridine in 550 ml. of tetrahydrofuran is added dropwise with slight cooling 341 ml. (0.52 mole) of butyl lithium solution in 550 ml. of ether. The dark colored solution is stirred for 5 hours at room tempera ture, and poured onto an excess of carbon dioxide in ether. The residual mixture of solid and ether is treated with dilute potassium carbonate. The aqueous layer is acidified with hydrochloric acid until pH=2, and the resulting product extracted with benzene, dried over sodium sulfate, filtered and concentrated. The residue is recrystallized from 1400 ml. of a benzene-n-heptane (1:1) mixture to yield 5-benzy1-5,6-dihydromorphanthridine-ll-canboxylic acid, M.P. 149-150. Repeated crystallizations raised the melting point to l55-156.

Analysis-Calcd. for C H NO C, 80.22; H, 5.81; N, 4.25. Found: C, 80.12; H, 5.75; N, 4.22.

6 EXAMPLE v Cyan omethyl 5-benzyl-S,6-dihydr0m0rphanthridine- I] -carboxylate EXAMPLE VI 5 -benzy l-5 ,6-dihyar0m 0rphanthridine-l 1 -carl10xamide An autoclave is charged with 27.6 g. (0.075 mole) of cyanomethyl 5 benzyl 5,6-dihydronionphanthridine-11- carboxylate and ml. of liquid ammonia, and the mix ture stirred 24 hours at room temperature. The excess of ammonia is evaporated, and the residue recrystalized from 700 ml. of ethanol to yield 5-benzyl-5,6-dihydromorphanthridine-ll-carboxamide, M.P'. 176.

Analysis.-Calcd. for C H N O: C, 80.45; H, 6.14; N, 8.53. Found: C, 80.52; H, 6.23; N, 8.25.

EXAMPLE VII N-methyl-5-methyl-5,6-dihydromorphanthridine- I-carboxamide EXAMPLE VIII 4-methyl-I-(5-methyl-5,6-dihyclro-]1- morphan thridinecarbonyl) -piperazine A mixture of 29.2 g. (0.1 mole) of cyanomethyl 5- methyl-S,6-dihydromorphanthridine-11 carboxylate and 100 g. of N-methylpiperazine is stirred. and heated for 24 hours in an autoclave. The reaction product is conextracted with ether, the ethereal extraction with C, 78.23; H, 5.47; N, 7.63.

AnalysisCa1cd. N, 10.22.

N, 9.31. Found: C, 66.36; H, 6.39; N, 9.06.

EXAMPLE IX N-(5-benzyl-5,6-dihydr0-JI-m0rphanlhridinecarbonyl)- pyrrolidine (0.05 mole) of cyanomethyl 5- benzyl-5,6-dihydromorphanthridine-11 carboxylate and concentrated, extracted with benzene, washed with dilute hydrochloric acid and water, the benzene solution is dried over potassium carbonate, filtered and concentrated to afford 17 g. of a brown syrup, which was distilled to yieldN-(S- benZyl-S, 6-dihydro-1 1-morphanthridinecarbonyl) -pyrrolidine, B.P. 250 (0.06 mm.).

Analysis.-Calcd. for G l-1 N 01 C, 81.65; H, 6.85; N, 7.32. Found: C, 81.62; H, 6.86; N, 7.52.

We claim:

1. A compound of the formula wherein A and A are members selected from the group consisting of hydrogen, a halo group, a lower alkoxy, -a lower alkyl, a lower alkyl-thio and trifluoromethyl; R is a member selected from the group consisting of hydrogen,

lower alkyl, phenyl-lower alkyl and allyl, and

is selected from groups in which R and R are selected from hydrogen, a lower alkyl, a lower alkenyl, phenyl, phenyl-lower alkyl, diphenylmethyl, trityl, naphthymethyl, a cycloalkyl of 5 to 7 carbon atoms, a cycloalkyl-lower alkyl in which the cycloalkyl has 5 to 7 carbon atoms and groups in which R3 is selected from morpholino, pyrrolidino, piperidino, piperazino and 4-lower alkyl piperazino.

4. A compound of claim 1 in which A and A are selected from hydrogen and halo, R is selected from hydrogen, lower alkyl and benzyl, and R and R are selected from hydrogen, lower alkyl and phenyl-lower alkyl.

5. A compound of claim 1 in which A and A are selected from hydrogen and halo, R is selected from hydrogen, lower alkyl and benzyl, and

is a group selected from 4-lower alkyl piperazino and pyrrolidino.

6. A compound of claim 1 in which A and A are hydrogen, -R is selected from methyl and benzyl, and R and R are hydrogen.

No references cited.

ALEX MAZEL, Primary Examiner. ALTON D. ROLLINS, Examiner 

1. A COMPOUND OF THE FORMULA 